Sorry, no video here. Which is too bad because it looks pretty cool.
// Blinking LEDs
// Simple program to test SPI with the RGB Matrix and Backpack from Sparkfun.
//
// Revised 2009.12.24
//
// Credits:
// Heather Dewey-Hagborg
// Arduino Forum user Little-Scale
// Daniel Hirschmann
// Arduino Forum user chessplayer
// SPI register bit positions
#define RX_IN 0
#define TX_OUT 1
#define CS 2
#define MOSI 3
#define MISO 4
#define SCK 5
// Ardrino Duemilanove pin numbers for SPI
#define CHIPSELECT 10 // CS
#define DATAOUT 11 // MOSI
#define DATAIN 12 // MISO (not used)
#define SPICLOCK 13 // SCK
// SparkFun RGB LED backpack officially supported colors
typedef unsigned char ledcolorType;
#define colorBlack 0x00
#define colorRed 0xe0
#define colorGreen 0x1c
#define colorBlue 0x03
#define colorOrange 0xfc
#define colorMagneta 0xe3
#define colorTeal 0x1f
#define colorWhite 0xff
#define colorLen 8
static const ledcolorType colors[colorLen] =
{
colorBlack, colorRed, colorGreen, colorBlue,
colorOrange, colorMagneta, colorTeal, colorWhite
};
// SparkFun RGB LED backpack frame geometry
#define rowLen 8
#define colLen 8
typedef struct
{
ledcolorType pixels[rowLen][colLen];
} frameType;
static void SetFrameToColor(frameType& frame, const ledcolorType color)
{
for (unsigned int col = 0; col < colLen; col++)
for (unsigned int row = 0; row < rowLen; row++)
frame.pixels[row][col] = color;
}
static void SetFrameToBlack(frameType& frame) {SetFrameToColor(frame, colorBlack);}
static unsigned char PickRandomColor(void) {return colors[random(colorLen)];}
static void ChangeOneRandomPixelToColor(frameType& frame, const ledcolorType color)
{
frame.pixels[random(rowLen)][random(colLen)] = color;
}
static void SetBackpackSelectStatus(const unsigned int status)
{
digitalWrite(CHIPSELECT, status); delayMicroseconds(500);
}
static void BackpackEnable(void) {SetBackpackSelectStatus(LOW);}
static void BackpackDisable(void) {SetBackpackSelectStatus(HIGH);}
static unsigned char WriteSPIByte(unsigned char data)
{
SPDR = data; while (!(SPSR & (1 << SPIF))); return SPDR;
}
static void SetBackpackDaisyChainLength(const unsigned int length)
{
BackpackEnable();
WriteSPIByte('%'); WriteSPIByte(length);
BackpackDisable();
}
static void WriteFrame(const frameType& frame)
{
BackpackEnable();
for (unsigned int row = 0; row < rowLen; row++)
for (unsigned int col = 0; col < colLen; col++)
WriteSPIByte(frame.pixels[row][col]);
BackpackDisable();
}
// The last real frame displayed
static frameType realframe;
// One time setup
void setup()
{
// Initialize the Arduino SPI pin directions
pinMode(CHIPSELECT, OUTPUT);
pinMode(DATAIN, INPUT);
pinMode(DATAOUT, OUTPUT);
pinMode(SPICLOCK, OUTPUT);
// Magical initialization of the SPI registers
volatile byte clr;
DDRB = (1 << CS) | (1 << MOSI) | (1 << SCK);
DDRD = (1 << TX_OUT);
SPCR = (1 << SPE) | (1 << MSTR) | (1 << SPR1);
SPSR = SPSR & 0xfe;
clr = SPSR; clr = SPDR;
// Set the backpack to its default state
BackpackDisable();
SetBackpackDaisyChainLength(1); // Be careful with this one
// Initial display is all black pixels
SetFrameToBlack(realframe); WriteFrame(realframe);
}
// Main loop
void loop()
{
delay(100);
ChangeOneRandomPixelToColor(realframe, PickRandomColor());
WriteFrame(realframe);
}
